Bacteria transformed into ‘hydrogen nanoreactors’ to produce clean fuel from sunlight

Researchers at the University of Oxford have achieved a significant advancement in the field of green hydrogen production.

Their innovative approach involves using bio-engineered bacteria termed “hydrogen nanoreactors” to create hydrogen fuel from water and sunlight.

This breakthrough has the potential to revolutionize the way hydrogen is produced, making it more sustainable and cost-effective.

“Our new study has provided a compelling alternative in the form of a robust and efficient biocatalyst,” said lead author Professor Wei Huang.

“This has the advantages of greater safety, renewability, and lower production costs all of which can improve long-term economic viability.”

Creating ‘hydrogen nanoreactors’ for clean energy

Green hydrogen is produced by splitting water molecules using renewable energy sources. This process is considered environmentally friendly because it does not generate any carbon dioxide emissions.

“However, current industrial hydrogen production depends heavily on fossil fuels, generating approximately 11.5–13.6 kilograms of CO2 emissions per kilogram of hydrogen produced,” added the researchers in a press release.

The researchers genetically modified a species of bacteria, Shewanella oneidensis, to enhance its ability to produce hydrogen.

“This species is ‘electroactive,’ meaning that it can transfer electrons to or from solid surfaces outside their cells,” explained the press release.

The researchers engineered the bacteria to concentrate electrons, protons, and a crucial enzyme named hydrogenase within a specific compartment of the cell. This compartment, known as the periplasmic space, is located between the inner and outer membranes of the bacteria.

By concentrating these components in a confined space, the researchers could increase the efficiency of hydrogen production.

Could be scaled up for ‘artificial leaves’

To further enhance the process, the team introduced a light-activated electron pump into the bacteria. This pump uses sunlight to move protons into the periplasmic space, providing the necessary ingredients for hydrogen production.

“Additionally, nanoparticles of reduced graphene oxide and ferric sulfate were introduced to enhance the electron transfer. Finally, the hydrogenase enzyme in the periplasmic space was also overexpressed,” highlighted the researchers.

These modifications resulted in a ten-fold increase in hydrogen yield compared to unmodified bacteria.

The researchers believe that this system could be scaled up to create “artificial leaves” coated with the engineered bacteria.

“When these artificial leaves are exposed to sunlight, they would immediately begin producing hydrogen,” asserted the team.

These leaves could then be used to generate hydrogen from sunlight on a large scale.

Sustainable hydrogen production

This breakthrough can significantly reduce the cost of green hydrogen production, making it a more viable alternative to fossil fuels.

The use of bio-engineered bacteria offers a sustainable and environmentally friendly approach to generating clean energy.

The researchers are optimistic that this technology will contribute to the transition towards a net-zero emissions future.

“Our bionanoreactor has suggested the potential of biocatalysts for clean energy production,” concluded co-author Professor Ian Thompson.

“The abiotic materials used in this work, including the graphene oxide and ferric sulfate nanoparticles, were synthesised by biological methods, making them more eco-friendly than traditional chemical approaches.”